tell sb to do sth 为什么要加to

tell sb to do sth 为什么要加to tell sb to do sth tell sb do sth.与tell sb to do sth. Sb tell sb to do sth造句 tell sb sth tell sb about sth tell sb to do sth tell sb not 用tell sth.tell sb.sth.tell sb.to do sth.tellsb.not to do sth tell sb doing sth还是tell sb to do sth 怎么变单三的句子?、tell sb sth、 tell sb about sth、 tell sb to do sth、 ask/tell sb.not to do sth 用tell sb to do sth造句 tell sb to do sth造句 Tell sb.not to do sth.造句